Process for producing masterbatch

Abstract

Provided is a method of producing a masterbatch, in which a reduction in the viscosity of a polyester resin is inhibited and thereby a metal salt compound can be incorporated in a large amount. This method is a method of producing a masterbatch that comprises 0.4 to 10 parts by mass of at least one metal salt compound selected from the group consisting of metal benzoates, metal aliphatic carboxylates, metal aromatic phosphates, metal salts of sulfonamide compounds and metal salts of sulfonimide compounds with respect to 100 parts by mass of a polyester resin, wherein when the polyester resin and the metal salt compound are fed to an extruder and kneaded, the cylinder temperature of the extruder is controlled in a range of (the melting point of the polyester resin—60° C.) to (the melting point of the polyester resin—10° C.).

Description

TECHNICAL FIELD[0001]The present invention relates to a method of producing a masterbatch in which a metal salt compound is incorporated into a polyester resin. More particularly, the present invention relates to a method of producing a masterbatch wherein, in the step of feeding a polyester resin and a metal salt compound to an extruder and kneading them, the cylinder temperature of the extruder is controlled to be lower than the melting point of the polyester resin.BACKGROUND ART[0002]As polyester resins that are obtained by polycondensation of a polycarboxylic acid and a polyhydric alcohol, for example, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate are known. Particularly, polyethylene terephthalate is a resin that has excellent transparency, heat resistance, chemical resistance, hygienic properties, staining properties, economic efficiency and the like; therefore, it is widely used in...

AI Technical Summary

Benefits of technology

The invention stops the reduction of melt viscosity, which allows for the stable production of a masterbatch. This also results in a molded article with excellent physical properties.

Problems solved by technology

Yet, in the production method disclosed in Patent Document 5, there are problems in that, due to a marked viscosity reduction and coloration that occur in association with decomposition of the polyester resin during the first step of kneading the polyester resin and the metal salt compound, stable production of a masterbatch cannot be achieved and the physical properties of a molded article obtained using the resulting masterbatch are deteriorated.

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